A plan to reform Germany's federal system has failed because of a dispute over control of education policy, several state premiers said on Friday. States have insisted on education remaining a core responsibility for them but federal government officials had wanted to have a say as well. The federal system was originally developed after World War II to secure a balance of power between state and federal governments. As part of the reform, fewer laws would have required state approval, which has been a problem for the federal government so far. Many bills have been blocked in Germany's upper house, the Bundesrat, which represents states' interests.